Question

A student investigated the effect of aged-grass compost (fertilizer madefrom decaying plant material) on the growth of bean plants. She thoughtthat the compost would provide extra nutrients and make plants growfaster. Thirty bean seeds were divided into three groups and planted indifferent flats (boxes). All seeds germinated after 12 days and wereallowed to grow for five days. The flats were each given the same amountof water and the same amount of light. Flat A was then fertilized with 3-month old compost; Flat B was given 6-month old compost and Flat Cwas given no compost. At the end of 14 days the height of each plant wasmeasured in centimeters. Which Flat was the control for this experiment?

Answer 1

In this experiment, the control group would be Flat C, because it has no compost, and the results obtained from it will show the growth of the plants in wild conditions, i.e without treatment (the composts of different maturity times).